1211021100391 has 2 divisors, whose sum is σ = 1211021100392. Its totient is φ = 1211021100390.

The previous prime is 1211021100313. The next prime is 1211021100433. The reversal of 1211021100391 is 1930011201121.

It is a strong prime.

It is an emirp because it is prime and its reverse (1930011201121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211021100391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211021130391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605510550195 + 605510550196.

It is an arithmetic number, because the mean of its divisors is an integer number (605510550196).

Almost surely, 2^{1211021100391} is an apocalyptic number.

1211021100391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211021100391 is an equidigital number, since it uses as much as digits as its factorization.

1211021100391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 22.

The spelling of 1211021100391 in words is "one trillion, two hundred eleven billion, twenty-one million, one hundred thousand, three hundred ninety-one".